Patterning method for preparing top-gate, bottom-contact organic field effect transistors

ABSTRACT

The present invention relates to a process for the preparation of a top-gate, bottom-contact organic field effect transistor on a substrate, which organic field effect transistor comprises source and drain electrodes, a semiconducting layer, a cured first dielectric layer and a gate electrode, and which process comprises the steps of: i) applying a composition comprising an organic semiconducting material to form the semiconducting layer, ii) applying a composition comprising a first dielectric material and a crosslinking agent carrying at least two azide groups to form a first dielectric layer, iii) curing portions of the first dielectric layer by light treatment, iv) removing the uncured portions of the first dielectric layer, and v) removing the portions of the semiconducting layer that are not covered by the cured first dielectric layer, wherein the first dielectric material comprises a star-shaped polymer consisting of at least one polymer block A and at least two polymer blocks B, wherein each polymer block B is attached to the polymer block A, and wherein at least 60 mol % of the repeat units of polymer block B are selected from the group consisting of Formulas (1A), (1B), (1C), (1D), (1E) and (1F), wherein R1, R2, R3, R4, R5, R6, R7 and R8 are independently and at each occurrence H or C1-C10-alkyl.

The present invention relates to a process for the preparation of atop-gate, bottom-contact organic field effect transistor and to a topgate, bottom-contact organic field effect transistor.

Organic field effect transistors (OFETs) can be used in manyapplications that require electronic functionalities such as displays,large-area sensors and radio-frequency identification (RFID) tags. OFETscan have a top-gate or bottom-gate architecture. Top-gate,bottom-contact organic field effect transistors can comprise, in thefollowing order, a substrate, source and drain electrodes, one organicsemiconducting layer, at least one dielectric layer and a gateelectrode.

U.S. Pat. No. 7,384,814 describes a method of manufacturing a top-gate,bottom contact organic field effect transistor with a patterned organicsemiconducting layer, in which process the organic semiconducting layerand the dielectric layer on top of the semiconducting layer arepatterned together in one step. In a preferred embodiment, thedielectric layer is light curable, and the patterning of thesemiconducting layer and the dielectric layer is performed by exposingthe dielectric layer to the appropriate light via a mask, removing thoseparts of the dielectric layer not cured by the light, followed byetching away those parts of the semiconducting layer not covered by thecured dielectric layer. Examples of dielectric layers that are lightcurable are HPR504, a formulation comprising ethyl lactate, novolacresin and 1-naphthalenesulfonic acid,6-diazo-5,6-dihydro-5-oxo-,1,1′,1″-(1,3,5-benzenetriyl) ester, andSC100, a cyclic polyisoprene.

It was the object of the present invention to provide a process for thepreparation of a top gate, bottom-contact organic field effecttransistor of improved performance, wherein the semiconducting layer andat least one dielectric layer are patterned together using low dosage UVlight treatment under ambient conditions.

This object is solved by the provided top-gate, bottom-contact organicfield effect transistor described herein.

The process of the present invention is a process for the preparation ofa top-gate, bottom-contact organic field effect transistor on asubstrate, which organic field effect transistor comprises source anddrain electrodes, a semiconducting layer, a cured first dielectric layerand a gate electrode, and which process comprises the steps of

-   -   i) applying a composition comprising an organic semiconducting        material to form the semiconducting layer,    -   ii) applying a composition comprising a first dielectric        material and a crosslinking agent carrying at least two azide        groups to form a first dielectric layer,    -   iii) curing portions of the first dielectric layer by light        treatment,    -   iv) removing the uncured portions of the first dielectric layer,        and    -   v) removing the portions of the semiconducting layer that are        not covered by the cured first dielectric layer,    -   wherein the first dielectric material comprises a star-shaped        polymer consisting of at least one polymer block A and at least        two polymer blocks B, wherein each polymer block B is attached        to the polymer block A, and wherein at least 60 mol % of the        repeat units of polymer block B are selected from the group        consisting of

wherein R¹, R², R³, R⁴, R⁵, R⁶, R⁷ and R⁸ are independently and at eachoccurrence H or C₁-C₁₀-alkyl.

If the star-shaped polymer is a polymer consisting of one polymerblock Aand two polymerblocks B, the star-shaped polymer is also called atriblockpolymer. C₁₋₄-alkyl, C₁₋₆-alkyl, C₁₋₁₀-alkyl, C₁₋₂₀-alkyl,C₁₋₃₀-alkyl and C₆₋₃₀-alkyl can be branched or unbranched (linear). Ifbranched, C₁₋₄-alkyl, C₁₋₆-alkyl, C₁₋₁₀-alkyl, C₁₋₂₀-alkyl andC₁₋₃₀-alkyl are preferably branched at the C2-atom. Examples ofC₁₋₄-alkyl are methyl, ethyl, butyl, iso-butyl, sec-butyl andtert-butyl. Examples of C₁₋₆-alkyl are methyl, ethyl, n-propyl,isopropyl, n-butyl, sec-butyl, isobutyl, tert-butyl, n-pentyl,neopentyl, isopentyl, n-(1-ethyl)propyl and n-hexyl. Examples ofC₁₋₁₀-alkyl are C₁₋₆-alkyl and n-heptyl, n-octyl, n-(2-ethyl)hexyl,n-nonyl, n-decyl. Examples of C₁₋₂₀-alkyl are C₁₋₁₀-alkyl and n-undecyl,n-dodecyl, n-undecyl, n-dodecyl, n-tridecyl, n-tetradecyl,n-(2-butyl)decyl, n-pentadecyl, n-hexadecyl, n-heptadecyl, n-octadecyl,n-nonadecyl, n-(2-hexyl)tetradecyl and n-icosyl (C₂₀). Examples ofC₁₋₃₀-alkyl are C₁₋₂₀-alkyl and n-docosyl (C₂₂), n-(2-decyl)dodecyl,n-tetracosyl (C₂₄), n-hexacosyl (C₂₆), n-octacosyl (C₂₈) andn-triacontyl (C₃₀). Examples of C₆₋₃₀-alkyl are n-hexyl, n-heptyl,n-octyl, n-(2-ethyl)hexyl, n-nonyl, n-decyl, n-undecyl, n-dodecyl,n-undecyl, n-dodecyl, n-tridecyl, n-tetradecyl, n-(2-butyl)decyl,n-pentadecyl, n-hexadecyl, n-heptadecyl, n-octadecyl, n-nonadecyl,n-(2-hexyl)tetradecyl, n-icosyl, n-docosyl (C₂₂), n-(2-decyl)dodecyl,n-tetracosyl (C₂₄), n-hexacosyl (C₂₆), n-octacosyl (C₂₈) andn-triacontyl (C₃₀).

Examples of C₆₋₁₄-aryl are phenyl and naphthyl.

Examples of 5 to 14 membered heteroaryl are

Examples of C₁₋₁₀-alkylene are methylene, ethylene, propylene, butylene,pentylene, hexylene, heptylene, octylene, nonylene and decylene.

Examples of C₂₋₁₀-alkylene are ethenylene, propenylene, butenylene,pentenylene, hexenylene, heptenylene, octenylene, nonenylene anddecenylene.

Examples of C₂₋₁₀-alkynylene are ethynylene, propynylene, butynylene,pentynylene, hexynylene, heptynylene, octynylene, nonynylene anddecynylene.

Examples of C₆₋₁₄-arylene are

Examples of C₅₋₈-cycloalkylene are cyclopentylene, cyclohexylene,cycloheptylene and cyclooctylene.

Examples of 5 to 14 membered heteroarylene are

An example of a polycyclic system containing at least one ring selectedfrom the group consisting of C₆₋₁₄-aromatic ring and 5 to 14 memberedheteroaromatic ring is

Examples of halogen are F, Cl, Br and I.

Preferably, R¹, R², R³, R⁴, R⁵ and R⁶ are independently and at eachoccurrence H or C₁₋₄-alkyl.

More preferably, R¹, R², R³, R⁴, R⁵ and R⁶ are H.

Preferably, at least 60 mol % of the monomer units of polymerblock B areselected from the group consisting of

wherein

R¹, R², R³, R⁴, R⁵, R⁶, R⁷ and R⁸ are independently and at eachoccurrence H or C₁₋₄-alkyl.

Examples of monomer units of formula 1A, 1B, 1C and 1D are

Examples of monomer units of formula 1E and 1F are

More preferably, at least 70 mol % of the monomer units of thepolymerblock B are selected from the group consisting of

wherein

R¹, R², R³, R⁴, R⁵ and R⁶ are independently and at each occurrence H orC₁₋₄-alkyl.

More preferably, at least 80 mol % of the monomer units of thepolymerblock B are selected from the group consisting of

wherein

R¹, R², R³, R⁴, R⁵ and R⁶ are H.

The polymerblock B can contain further monomer units, such as monomerunits (4A), (4C), (4D), (4E) or (4F). However, most preferred,polymerblock B essentially consists of monomer units selected from thegroup consisting of (1A), (1B), (1C), (1D), (1E), (1F), (1G), (1H) and(1I).

The polymerblock A can consist of any suitable monomer units.

Preferably, at least 80 mol % of the monomer units of polymerblock A areselected from the group consisting of

wherein

R²⁰, R²¹, R²², R²³, R²⁴, R²⁵ and R²⁶ are independently and at eachoccurrence selected from the group consisting of H, C₆₋₁₄-aryl, 5 to 14membered heteroaryl and C₁₋₃₀-alkyl, and

R^(a) is C(O)OH, C(O)OC₁₋₃₀-alkyl, C(O)—H, C(O)C₆₋₁₄-aryl,C(O)N(C₁₋₃₀-alkyl)₂, C(O)N(C₆₋₁₄-aryl)₂, C(O)N(C₁₋₃₀-alkyl)(C₆₋₁₄-aryl),C(O)—C₆₋₁₄-aryl, C(O)—C₁₋₃₀-alkyl, O—C₆₋₁₄-aryl, O—C₁₋₃₀-alkyl,OC(O)C₁₋₃₀-alkyl, OC(O)C₆₋₁₄-aryl or CN,

-   -   wherein    -   C₆₋₁₄-aryl and 5-14 membered heteroaryl can be substituted with        one or more substituents selected from the group consisting of        C₁₋₁₀-alkyl, C(O)OH, C(O)OC₁₋₁₀-alkyl, C(O)phenyl,        C(O)N(C₁₋₁₀-alkyl)₂, C(O)N(phenyl)₂, C(O)N(C₁₋₁₀-alkyl)(phenyl),        C(O)-phenyl, C(O)—C₁₋₁₀-alkyl, OH, O-phenyl, O—C₁₋₁₀-alkyl,        OC(O)C₁₋₁₀-alkyl, OC(O)-phenyl, ON and NO₂, and    -   C₁₋₃₀-alkyl can be substituted with one or more substituents        selected from the group consisting of phenyl, C(O)OH,        C(O)OC₁₋₁₀-alkyl, C(O)phenyl, C(O)N(C₁₋₁₀-alkyl)₂,        C(O)N(phenyl)₂, C(O)N(C₁₋₁₀-alkyl)(phenyl), C(O)-phenyl,        C(O)—C₁₋₁₀-alkyl, O-phenyl, O—C₁₋₁₀-alkyl, OC(O)C₁₋₁₀-alkyl,        OC(O)-phenyl, Si(C₁₋₁₀-alkyl)₃, Si(phenyl)₃, ON and NO₂,

n is an integer from 1 to 3,

and

L²⁰ is C₁₋₁₀-alkylene, C₂₋₁₀-alkenylene, C₂₋₁₀-alkynylene, C₆₋₁₄-aryleneor S(O).

Examples of monomer units 4A are

An examples of a monomer unit 4B is

Examples of monomer units 4C are

More preferably, at least 80 mol % of the monomer units of polymerblockA are selected from the group consisting of

wherein

R²⁰, R²¹ and R²² are independently selected from the group consisting ofH, C₆₋₁₄-aryl, 5 to 14 membered heteroaryl and C₁₋₃₀-alkyl, and

R^(a) is C(O)OC₁₋₃₀-alkyl,

-   -   wherein    -   C₆₋₁₄-aryl and 5-14 membered heteroaryl can be substituted with        one or more C₁₋₁₀-alkyl, and    -   C₁₋₃₀-alkyl can be substituted with one or more substituents        selected from the group consisting of Si(C₁₋₁₀-alkyl)₃ and        Si(phenyl)₃,

and

n is an integer from 1 to 3, and

L²⁰ is C₁₋₁₀-alkylene or C₆₋₁₄-arylene.

Even more preferably, at least 90 mol % of the monomer units ofpolymerblock A is a monomer unit selected from the group consisting of

wherein

R²⁰ and R²¹ are independently selected from the group consisting of Hand C₆₋₁₄-aryl,

-   -   wherein    -   C₆₋₁₄-aryl can be substituted with one or more C₁₋₁₀-alkyl,

and

L²⁰ is C₆₋₁₄-arylene.

Most preferably, at least 90 mol % of the monomer units of polymerblockA is a monomer unit selected from the group consisting of

wherein

R²⁰ and R²¹ are independently selected from the group consisting of Hand phenyl, and L²⁰ is phenylene.

The polymerblock A can additionally contain further monomer units, suchas the monomer units (1A), (1B), (1C), (1D), (1E), (1F), (1G), (1H) and(1I). However, most preferred, polymerblock A essentially consists ofmonomer units selected from the group consisting of (4A), (4B), (4C),(4D), (4E) and (4F).

In one embodiment of the present invention, the star-shaped polymerconsists of one polymerblock A and more than two polymerblocks B.

In another embodiment of the present invention, the star-shaped polymeris a triblock polymer consisting of one polymerblock A and twopolymerblocks B.

Preferably, the star-shaped polymer is a triblock polymer consisting ofone polymerblock A and two polymerblocks B, wherein each polymerblock Bis attached to the polymerblock A, and wherein

at least 60 mol % of the monomer units of polymerblock B are selectedfrom the group consisting of

wherein

R¹, R², R³, R⁴, R⁵, R⁶, R⁷ and R⁸ are independently and at eachoccurrence H or C₁₋₄-alkyl,

with the proviso that at least one of the monomer units (1A) and (1B) ispresent, and that the ratio of [mols of monomer units (1A) and(1B)]/[mols of monomer units (1A), (1B), (1C) and (1D)] is at least 30%.

Preferably, at least 70 mol % of the monomer units of the polymerblock Bof the triblock polymer are selected from the group consisting of

wherein

R¹, R², R³, R⁴, R⁵ and R⁶ are independently and at each occurrence H orC₁₋₄-alkyl, with the proviso that at least one of the monomer units (1A)and (1B) is present, and that the ratio of [mols of monomer units (1A)and (1B)]/[mols of monomer units (1A), (1B), (1C) and (1D)] is at least50%.

More preferably, at least 80 mol % of the monomer units of thepolymerblock B of the triblock polymer are selected from the groupconsisting of

wherein

R¹, R², R³, R⁴, R⁵, R⁶ are H,

with the proviso that at least one of the monomer units (1A) and (1B) ispresent, and that the ratio of [mols of monomer units (1A) and(1B)]/[mols of monomer units (1A), (1B), (1C) and (1D)] is at least 70%.

The polymerblock B of the triblock polymer can contain further monomerunits, such as monomer units (4A), (4C), (4D), (4E) or (4F). However,most preferred, polymerblock B essentially consists of monomer unitsselected from the group consisting of (1A), (1B), (1C), (1D), (1E),(1F), (1G), (1H) and (1I).

Preferably, at least 80 mol % of the monomer units of polymerblock A ofthe triblock polymer are selected from the group consisting of

wherein

R²⁰, R²¹, R²², R²³, R²⁴, R²⁵ and R²⁶ are independently and at eachoccurrence selected from the group consisting of H, C₆₋₁₄-aryl, 5 to 14membered heteroaryl and C₁₋₃₀-alkyl, and

R^(a) is C(O)OH, C(O)OC₁₋₃₀-alkyl, C(O)—H, C(O)C₆₋₁₄-aryl,C(O)N(C₁₋₃₀-alkyl)₂, C(O)N(C₆₋₁₄-aryl)₂, C(O)N(C₁₋₃₀-alkyl)(C₆₋₁₄-aryl),C(O)—C₆₋₁₄-aryl, C(O)—C₁₋₃₀-alkyl, O—C₆₋₁₄-aryl, O—C₁₋₃₀-alkyl,OC(O)C₁₋₃₀-alkyl, OC(O)C₆₋₁₄-aryl or CN,

-   -   wherein    -   C₆₋₁₄-aryl and 5-14 membered heteroaryl can be substituted with        one or more substituents selected from the group consisting of        C₁₋₁₀-alkyl, C(O)OH, C(O)OC₁₋₁₀-alkyl, C(O)phenyl,        C(O)N(C₁₋₁₀-alkyl)₂, C(O)N(phenyl)₂, C(O)N(C₁₋₁₀-alkyl)(phenyl),        C(O)-phenyl, C(O)—C₁₋₁₀-alkyl, OH, O-phenyl, O—C₁₋₁₀-alkyl,        OC(O)C₁₋₁₀-alkyl, OC(O)-phenyl and CN and NO₂, and    -   C₁₋₃₀-alkyl can be substituted with one or more substituents        selected from the group consisting of with phenyl, C(O)OH,        C(O)OC₁₋₁₀-alkyl, C(O)phenyl, C(O)N(C₁₋₁₀-alkyl)₂,        C(O)N(phenyl)₂, C(O)N(C₁₋₁₀-alkyl)(phenyl), C(O)-phenyl,        C(O)—C₁₋₁₀-alkyl, O-phenyl, O—C₁₋₁₀-alkyl, OC(O)C₁₋₁₀-alkyl,        OC(O)-phenyl, Si(C₁₋₁₀-alkyl)₃, Si(phenyl)₃ and CN and NO₂,

and

n is an integer from 1 to 3.

More preferably, at least 80 mol % of the monomer units of polymerblockA of the triblock polymer are selected from the group consisting of

wherein

R²⁰, R²¹ and R²² are independently selected from the group consisting ofH, C₆₋₁₄-aryl, 5 to 14 membered heteroaryl and C₁₋₃₀-alkyl, and

R^(a) is C(O)OC₁₋₃₀-alkyl,

-   -   wherein    -   C₆₋₁₄-aryl and 5-14 membered heteroaryl can be substituted with        one or more C₁₋₁₀-alkyl, and    -   C₁₋₃₀-alkyl can be substituted with one or more substituents        selected from the group consisting of Si(C₁₋₁₀-alkyl)₃ and        Si(phenyl)₃,

and

n is an integer from 1 to 3.

Most preferably, at least 80 mol % of the monomer units of polymerblockA of the triblock polymer are monomer units selected from the groupconsisting of

wherein

R²⁰ and R²¹ are independently selected from the group consisting of Hand C₆₋₁₄-aryl,

-   -   wherein    -   C₆₋₁₄-aryl can be substituted with one or more C₁₋₁₀-alkyl.

The polymerblock A of the triblock polymer can additionally containfurther monomer units, such as the monomer units (1A), (1B), (1C), (1D),(1E), (1F), (1G), (1H) and (1I). However, most preferred, polymerblock Aof the triblock polymer essentially consists of monomer units selectedfrom the group consisting of (4A), (4C), (4D), (4E) and (4F).

More preferably, the star-shaped polymer is a triblock polymerconsisting of one polymerblock A and two polymerblocks B, wherein

at least 70 mol % of the monomer units of the polymerblock B areselected from the group consisting of

wherein

R¹, R², R³, R⁴, R⁵ and R⁶ are independently and at each occurrence H orC₁₋₄-alkyl,

with the proviso that at least one of the monomer units 1A and 1B ispresent, and that the ratio of [mols of monomer units 1A and 1B]/[molsof monomer units 1A, 1B, 1C and 1D] is at least 50%,

and

at least 80 mol % of the monomer units of polymerblock A is a monomerunit of formula

wherein

R²⁰ is H, and

R²¹ is at each occurrence C₆₋₁₄-aryl,

-   -   wherein    -   C₆₋₁₄-aryl can be substituted with one or more C₁₋₁₀-alkyl.

Even more preferably, the star-shaped polymer of the present inventionis a triblock polymer consisting of one polymerblock A and twopolymerblocks B, wherein at least 80 mol % of the monomer units of thepolymerblock B are selected from the group consisting of

wherein

R¹, R², R³, R⁴, R⁵ and R⁶ are H, with the proviso that at least one ofthe monomer units 1A and 1B is present, and that the ratio of [mols ofmonomer units 1A and 1B]/[mols of monomer units 1A, 1B, 1C and 1D] is atleast 70%, and

at least 90 mol % of the monomer units of polymerblock A is a monomerunit of formula

wherein

R²⁰ is H and, R²¹ is phenyl.

The following definitions and preparation methods regarding polymers,including definitions and preparation methods regarding polymerblock Band polymerblock A, apply to the star-shaped polymers, including thetriblock polymers.

Preferably, the weight ratio of polymerblock A/total polymerblocks B isfrom 60/40 to 96/4. More preferably, the weight ratio of polymerblockA/total polymerblocks B is from 70/30 to 96/4. Most preferably, theweight ratio of polymerblock A/total polymerblocks B is from 76/24 to94/4.

Preferably, the star-shaped polymers have a number average molecularweight Mn of at least 60000 g/mol and a weight average molecular weightMw of at least 70000 g/mol, both as determined by gel permeationchromatography.

More preferably, the star-shaped polymers have a number averagemolecular weight Mn of at least 100000 g/mol and a weight averagemolecular weight Mw of at least 120000 g/mol, both as determined by gelpermeation chromatography.

Most preferably, the star-shaped polymers have a number averagemolecular weight Mn of at least 120000 g/mol and a weight averagemolecular weight Mw of at least 150000 g/mol, both as determined by gelpermeation chromatography.

It is assumed that the total monomers used in the preparation ofpolymerblock B are incorporated in polymerblock B.

It is assumed that mol % of the monomer units (1A), (1B), (1C) and (1D)is equal to mol % of monomer

wherein

R¹, R², R³, R⁴, R⁵ and R⁶ are as defined for monomer units (1A), (1B),(1C) and (1D), based on total mols of monomers used in the preparationof polymerblock B.

The ratio of [mols of monomer units (1A) and (1B)]/[mols monomer units(1C) and (1D)] can be determined from the integrated signals obtained by¹H-NMR allowing sufficient time for full relaxation of the signals. Fromthis data, the ratio of [mols of monomer units (1A) and (1B)]/[mols ofmonomer units (1A), (1B), (1C) and (1D)] can be calculated.

It is assumed that mol % of the monomer units (1E) and (1F) inpolymerblock B is equal to mol % of monomer

wherein

R¹, R², R³, R⁴, R⁵, R⁶, R⁷ and R⁸ are as defined for monomer units (1E)and (1F), based on total mols of monomers used in the preparation ofpolymerblock B.

It is assumed that mol % of the monomer units (1G) in polymerblock B isequal to mol % of monomer

based on total mols of monomers used in the preparation of polymerblockB.

It is assumed that mol % of the monomer units (1H) in polymerblock B isequal to mol % of monomer

based on total mols of monomers used in the preparation of polymerblockB.

It is assumed that mol % of the monomer units (1I) in polymerblock B isequal to mol % of monomer

based on total mols of monomers used in the preparation of polymerblockB.

It is assumed that all monomers used in the preparation of polymerblockA are incorporated in polymerblock A.

Thus, it is assumed that mol % of the monomer units (4A) in polymerblockA is equal to mol % of monomer

wherein

R²⁰ and R²¹ are as defined for monomer unit (4A), based on the totalmols of monomers used in the preparation of polymerblock A.

It is assumed that mol % of the monomer units (4B) in polymerblock A isequal to the mol % of monomer

wherein L²⁰ is as defined for monomer units (4B), based on the totalmols of monomers used in the preparation of polymerblock A.

It is assumed that mol % of the monomer units (4C) in polymerblock A isequal to the mol % of monomer

wherein

R²² and R^(a) are is as defined for monomer unit (4C), based on thetotal mols of monomers used in the preparation of polymerblock A.

It is assumed that mol % of the monomer units (4D) in polymerblock A isequal to the mol % of monomer

wherein

n is as defined for monomer unit (4D),

based on the total mols of monomers used in the preparation ofpolymerblock A.

It is assumed that mol % of the monomer units (4E) in polymerblock A isequal to the mol % of monomer

wherein

R²³, R²⁴, R²⁵ and R²⁶, are as defined for monomer unit (4E),

based on the total mols of monomers used in the preparation ofpolymerblock A.

It is assumed that mol % of the monomer units (4F) in polymerblock A isequal to the mol % of monomer

wherein

R²³, R²⁴, R²⁵ and R²⁶ are as defined for monomer unit (4F), based on thetotal mols of monomers used in the preparation of polymerblock A.

The star-shaped polymers consisting of one polymerblock A and at leasttwo polymerblocks B can be prepared by polymerisation methods known inthe art.

For example, polymerbock A can be prepared by anionic polymerisationmethods using at least 80 mol % of monomers selected from the groupconsisting of

wherein

R¹, R², R³, R⁴, R⁵, R⁶, R⁷ and R⁸ are as defined for monomer units (4A),(4B), (4C), (4D), (4E) and (4F),

based on total mols of monomers used in the preparation of polymerblockA.

For example, polymerbock B can be prepared by anionic polymerisationmethods using at least 60 mol % of monomers selected from the groupconsisting of

wherein

R¹, R², R³, R⁴, R⁵, R⁶, R⁷ and R⁸ are as defined for monomer units (1A),(1B), (1C) and (1D), based on total mols of monomers used in thepreparation of polymerblock B.

The anionic polymerisation methods are usually initiated by amono-functional initiator such as n-BuLi or sec-BuLi, or a bi-functionalinitiator such as 1,4-dilithio-1,1,4,4-tetraphenylbutane.

The anionic polymerisation methods are usually performed in a suitableaprotic solvent or mixture of aprotic solvents. The aprotic solvent canbe a polar solvent such as tetrahydrofuran or a non-polar solvent suchas toluene or cyclohexane.

The weight ratio of total monomer/solvent is usually in the range of1/100 to 40/100 (weight/weight), more preferably in the range of 5/10 to30/100 (weight/weight).

The anionic polymerisations are usually performed at a temperature from30 to 80° C., preferably 50 to 80° C.

The anionic polymerisations are usually terminated by addition of aprotic solvent such as water or isopropanol.

Practical details of performing anionic polymerizations are describede.g. by Maurice Morton in “Anionic Polymerization: Principles andPractice”, Academic Press, New York, 1983, and by Henry Hsieh, RodericP. Quirk Anionic Polymerization: Principles and Practical Applications,Marcel Dekker, New York, 1996.

For example, polymerbock B can be prepared by ring-opening metathesispolymerisation (ROMP) using at least 60 mol % of monomers selected fromthe group consisting of

based on total mols of monomers used in the preparation of polymerblockB.

The ring-opening metathesis polymerisation methods are usually performedin the presence of a suitable catalyst such Schrock catalyst or Grubbs'catalyst. The ring-opening metathesis polymerisation methods can beterminated by addition of an aldehyde.

Proper selection of the catalyst and performing ROMP can be taken fromthe “Handbook of Metathesis, Volume 1-3” by Robert H. Grubbs et at.2015, Wiley-VCH, Weinheim, and Robert H. Grubbs in Handbook ofMetathesis (Wiley-VCH, Weinheim, 2003).

If the star-shaped polymer is a triblock polymer consisting of onepolymerblock A and two polymerblocks B, the following preparationmethods may be used: “sequential addition of monomers”, “bifunctionalinitiation” or “bifunctional coupling”.

“Sequential addition of monomers” by anionic polymerisation can involveproviding a mono-functional initiator, such as n-BuLi or sec-BuLi,followed by addition of the monomers for the first polymerblock B,followed by addition of the monomers for the polymerblock A, followed byaddition of the monomers for the second polymerblock B, followed bytermination with a protic solvent.

“Bifunctional initiation” by anionic polymerisation can involveproviding a bifunctional initiator such as1,4-dilithio-1,1,4,4-tetraphenylbutane, followed by addition of themonomers of polymerblock A, followed by addition of the monomers ofpolymerblocks B, followed by termination with a protic solvent. In thefinal polymer, the bifunctional initiator becomes part of polymerblockA.

“Bifunctional coupling” can involve coupling of polymerblock A carryingtwo terminal CH═O groups with polymerblock B prepared either by anionicpolymerisation using a mono-functional initiator or by ring-openingmetathesis polymerisation (ROMP).

“Bifunctional coupling” can also involve coupling of polymerblock Aprepared by anionic polymerisation using a bifunctional initiator withpolymerblock B carrying a CH═O group.

Polymerblock A canning two terminal CH═O groups can be prepared byanionic polymerisation using a bifunctional initiator, followed bytermination with a reagent containing a group causing the terminationand in addition an aldehyde group or protected aldehyde group, and, if aprotected aldehyde group is present, deprotecting the protected aldehydegroup.

Polymerblock B carrying a CH═O group can be prepared either by anionicpolymerisation using a monofunctional initiator or by ring-openingmetathesis polymerisation (ROMP), both followed by termination with areagent containing a group causing the termination and in addition analdehyde group or protected aldehyde group, and, if a protected aldehydegroup is present, deprotecting the protected aldehyde group.

Examples of reagents containing a group causing the termination and inaddition an aldehyde group are O═CH—(CH₂)₂—Cl, O═CH-phenylene-CH₂Cl andO═CH—CH₂—Si(Me)₂Cl.

Examples of reagents containing a group causing the termination and inaddition a protected aldehyde group are O═CH—(CH₂)₂—C(OCH₃)₂ orO═CH-phenylene-C(OCH₃)₂. The protected aldehyde group can be deprotectedby hydrolysis in the presence of acetic acid.

A comprehensive overview for making end-functionalized polymers byprotected functionalized termination agents and initiators are given byA. Hirao and M. Hayashi in “Recent advance in syntheses and applicationsof well-defined end functionalized polymers by means of anionic livingpolymerization”, Acta Polymerica 1999, Vol. 50, page 219 to 231.

If the polymer is a polymer consisting of one polymerblock A and morethan two polymerblocks B, a so-called “star-shaped polymer”, thefollowing preparation methods may be used: “multifunctional initiation”or “multifunctional coupling”.

For example, “multifunctional initiation” by anionic polymerisation caninvolve providing a multifunctional initiator, followed by addition ofthe monomers of polymerblock A, followed by addition of the monomers ofpolymerblocks B. In the final polymer, the multifunctional initiatorbecomes part of polymerblock A. If, for example, polymerblock A mainlycontains mainly monomer units of formula (1A), the multifunctionalinitiator can be an oligomer obtained by polymerisation ofdivinylbenzene, diphenylethylene and styrene in the presence of amono-functional initiator, usually a lithium organic compound such asn-BuLi or sec-BuLi.

For example, “Multifunctional coupling” by anionic polymerisation caninvolve providing a mono-functional initiator, usually a lithium organiccompound such as n-BuLi or sec-BuLi, followed by addition of themonomers for the polymerblocks B, followed by addition of the monomersof polymerblock A, followed by addition of a multifunctional couplingagent such as 1,2-bis(trichlorosilyl)ethane.

Depending on the monomer units of polymerblock A and polymerblock B, asuitable preparation method can be chosen.

Preferably, the crosslinking agent carrying at least two azide groups isa crosslinking agent carrying two azide groups.

Preferably, the crosslinking agent carrying two azide groups is offormula

wherein

a is 0 or 1,

R⁵⁰ is at each occurrence selected from the group consisting of H,halogen, SO₃M and C₁₋₂₀-alkyl, which C₁₋₂₀-alkyl can be substituted withone or more halogen,

-   -   wherein M is H, Na, K or Li, and

L⁵⁰ is a linking group.

Preferably, a is 0.

Preferably, R⁵⁰ is at each occurrence selected from the group consistingof F, SO₃M and C₁₋₂₀-alkyl, which C₁₋₂₀-alkyl can be substituted withone or more F,

wherein M is Na, K or Li.

More preferably, R⁵⁰ is at each occurrence F.

L⁵⁰ can be any suitable linking group.

Preferably, L⁵⁰ is a linking group of formula

wherein

b, c, d, e, f, g and h are independently from each other 0 or 1,provided that b, c, d, e, f, g and h are not all at the same time 0,

W¹, W², W³ and W⁴ are independently selected from the group consistingof C(O), C(O)O, C(O)—NR⁵¹, So₂—NR⁵¹, NR⁵¹, N⁺R⁵¹R⁵¹, CR⁵¹═CR⁵¹ andethynylene

-   -   wherein    -   R⁵¹ is at each occurrence H or C₁₋₁₀-alkyl, or two R⁵¹ groups,        which can be from different W¹, W², W³ and W⁴ groups, together        with the connecting atoms form a 5, 6 or 7 membered ring, which        may be substituted with one to three C₁₋₆-alkyls,

Z¹, Z² and Z³ are independently selected from the group consisting ofC₁₋₁₀-alkylene, C₅₋₈-cycloalkylene, C₆₋₁₄-arylene, 5 to 14 memberedheteroarylene and a polycyclic system containing at least one ringselected from C₆₋₁₄-aromatic ring and 5 to 14 membered heteroaromaticring,

-   -   wherein    -   C₁₋₁₀-alkylene, C₅₋₈-cycloalkylene, C₆₋₁₄ membered arylene, 5 to        14 membered heteroarylene and polycyclic system containing at        least one ring selected from C₆₋₁₄-aromatic ring and 5 to 14        membered heteroaromatic ring can be substituted with one to five        C₁₋₂₀-alkyl or phenyl.

Examples of linking groups L⁵⁰ are

More preferably, L⁵⁰ is a linking group of formula

wherein

b, c, d, e, f, g and h are independently from each other 0 or 1,provided that at least one of c, e, and g is 1,

W¹, W², W³ and W⁴ are independently from each other selected from thegroup consisting of C(O), C(O)O, C(O)—NR⁵¹, SO₂—NR⁵¹, NR⁵¹, N⁺R⁵¹R⁵¹,CR⁵¹═CR⁵¹ and ethynylene

-   -   wherein    -   R⁵¹ is at each occurrence H or C₁₋₁₀-alkyl, or two R⁵¹ groups,        which can be from different W¹, W², W³ and W⁴ groups, together        with the connecting atoms form a 5, 6 or 7 membered ring, which        may be substituted with one to three C₁₋₆-alkyls,

Z¹, Z² and Z³ are independently from each other selected from the groupconsisting of C₁₋₁₀-alkylene, C₅₋₈-cycloalkylene, C₆₋₁₄-arylene, 5 to 14membered heteroarylene and polycyclic system containing at least onering selected from C₆₋₁₄-aromatic ring and 5 to 14 memberedheteroaromatic ring,

-   -   wherein    -   C₁₋₁₀-alkylene, C₅₋₈-cycloalkylene, C₆₋₁₄ membered arylene, 5 to        14 membered heteroarylene and polycyclic system containing at        least one ring selected from C₆₋₁₄-aromatic ring and 5 to 14        membered heteroaromatic ring can be substituted with one to five        C₁₋₂₀-alkyl or phenyl,    -   provided at least one of Z¹, Z² and Z³ is C₆₋₁₄-arylene, 5 to 14        membered heteroarylene or polycyclic system containing at least        one ring selected from C₆₋₁₄-aromatic ring and 5 to 14 membered        heteroaromatic ring.

Most preferably, L⁵⁰ is a linking group of formula

wherein

b, c, d, e, f, g and h are independently from each other 0 or 1,provided that at least one of c, e, and g is 1,

W¹, W², W³ and W⁴ are independently from each other selected from thegroup consisting of C(O), CR⁵¹═CR⁵¹ and ethynylene

-   -   wherein    -   R⁵¹ is H,

Z¹, Z² and Z³ are independently from each other selected from the groupconsisting of C₁₋₁₀-alkylene, C₆₋₁₄-arylene, 5 to 14 memberedheteroarylene, and polycyclic system containing at least one ringselected from C₆₋₁₄-aromatic ring and 5 to 14 membered heteroaromaticring,

-   -   wherein    -   C₁₋₁₀-alkylene, C₆₋₁₄ membered arylene, 5 to 14 membered        heteroarylene and polycyclic system containing at least one ring        selected from C₆₋₁₄-aromatic ring and 5 to 14 membered        heteroaromatic ring can be substituted with one or two        C₁₋₂₀-alkyl or phenyl,

provided at least one of Z¹, Z² and Z³ is C₆₋₁₄-arylene, 5 to 14membered heteroarylene or polycyclic system containing at least one ringselected from C₆₋₁₄-aromatic ring and 5 to 14 membered heteroaromaticring.

In particular, L⁵⁰ is

wherein R¹² is C₁₋₂₀-alkyl.

The preparation of crosslinking agents carrying at least two azidegroups are described in various publications, for example WO2015/004563, Cai, S. X.; Glenn, D. J.; Kanskar, M.; Wybourne, M. N.;Keana, J. F. W. Chem. Mater. 1994, 6, 1822-1829, Van, M.; Cai, S. X.;Wybourne, M. N.; Keana, J. F. W. J. Mater. Chem. 1996, 6, 1249-1252,Touwslager, F. J.; Willard, N. P.; Leeuw, D. M. Applied Physics Letters2002, 81, 4556, WO 04/100282, WO 2007/004995, WO 2009/068884, Png,R.-Q.; Chia, P.-J.; Tang, J.-C.; Liu, B.; Sivaramakrishnan S.; Zhou, M.;Khong, S.-H.; Chan, H. S. O.; Burroughes, J. H.; Chua, L.-L.; Friend, R.H.; Ho, P. K. H. Nature Materials 2010, 9(2), 152-152, and WO2011/068482.

The composition comprising the first dielectric material and acrosslinking agent carrying at least two azide groups can also comprisea solvent. The solvent can be any suitable solvent or solvent mixture.Preferably, the solvent is a polar aprotic solvent or mixture of polaraprotic solvents. Examples of polar aprotic solvents are ethyl acetate,butyl acetate, acetone, cyclopentanone, tetrahydrofuran, propyleneglycol monomethyl ether acetate, acetonitrile, dimethylformamide anddimethylsulfoxide. Preferred polar aprotic solvents are butyl acetate,cyclopentanone and propylene glycol monomethyl ether acetate, inparticular cyclopentanone and propylene glycol monomethyl ether acetate.

Preferably, the composition comprising a first dielectric material and acrosslinking agent carrying at least two azide groups is a solution andcomprises

-   -   i) 0.1 to 500 mg of the first dielectric material based on 1000        mg of the composition,    -   ii) 0.1 to 20% by weight of the crosslinking agent carrying at        least two azide groups based on the weight of the first        dielectric material, and    -   iii) a solvent.

More preferably, the composition comprising a first dielectric materialand a crosslinking agent carrying at least two azide groups is asolution and comprises

-   -   i) 0.1 to 250 mg of the first dielectric material based on 1000        mg of the composition,    -   ii) 0.1 to 15% by weight of the crosslinking agent carrying at        least two azide groups based on the weight of the first        dielectric material, and    -   iii) a solvent.

Most preferably, the composition comprising a first dielectric materialand a crosslinking agent carrying at least two azide groups is asolution and comprises

-   -   i) 10 to 100 mg of the first dielectric material based on 1000        mg of the composition,    -   ii) 1 to 10% by weight of the crosslinking agent carrying at        least two azide groups based on the weight of the first        dielectric material, and    -   iii) a solvent.

The composition comprising a first dielectric material and acrosslinking agent carrying at least two azide groups can be prepared bymixing the first dielectric material, the crosslinking agent carrying atleast two azide groups, and optionally the solvent.

The organic semiconducting material can be any organic semiconductingmaterial known in the art. The organic semiconducting material can be asmall molecule or a polymer.

Examples of organic semiconducting materials are polycyclic aromatichydrocarbons consisting of linearly-fused aromatic rings such asanthracene, pentacene and derivatives thereof, polycyclic aromatichydrocarbons consisting of two-dimensional fused aromatic rings such asperylene, perylene diimide derivatives, peiylene dianhydride derivativesand naphthalene diimide derivatives, triphenylamine derivatives,oligomers and polymers containing aromatic units such as oligothiophene,oligophenylenevinylene, polythiophene, polythienylenevinylenepolyparaphenylene, polypyrrole and polyaniline, hydrocarbon chains suchas polyacetylenes, and diketopyrrolopyrrole-based materials.

For example, bis-alkynyl substituted polycyclic aromatic hydrocarbonsconsisting of linearly-fused aromatic rings are described inWO2007/068618.

For example, perylene diimide derivatives, perylene dianhydridederivatives and naphthalene diimide derivatives are described inWO2007/074137, WO2007/093643, WO2009/024512, WO2009/147237,WO2012/095790, WO2012/117089, WO2012/152598, WO2014/033622,WO2014/174435 and WO2015/193808.

For example, polymers comprising thiophene units are described inWO2010/000669, polymers comprising benzothiadiazol-cyclopentadithiopheneunits are described in WO2010/000755, polymers comprisingdithienobenzathienothiophene units are described in WO2011/067192,polymers comprising dithienophthalimide units are described inWO2013/004730, polymers comprising thienothiophene-2,5-dione units asdescribed in WO2012/146506, and polymers comprising Isoindigo-basedunits are described in WO2009/053291.

For example, diketopyrrolopyrrole-based materials and their synthesisare described in WO2005/049695, WO2008/000664, WO2010/049321,WO2010/049323, WO2010/108873, WO2010/136352, WO2010/136353,WO2012/041849, WO2012/175530, WO2013/083506, WO2013/083507 andWO2013/150005.

A summary on diketopyrrolopyrrole (DPP) based polymers suitable assemiconducting material in organic field effect transistors are alsogiven in Christian B. Nielsen, Mathieu Turbiez and lain McCulloch,Advanced Materials 2013, 25, 1859 to 1880.

Preferably, the organic semiconducting material is at least onediketopyrrolopyrrole-based material.

Preferably, the diketopyrrolopyrrole-based material is

-   -   i) a diketopyrrolopyrrole-based polymer comprising units of        formula

wherein

R³⁰ is at each occurrence C₁₋₃₀-alkyl, C₂₋₃₀-alkenyl or C₂₋₃₀-alkynyl,wherein C₁₋₃₀-alkyl, C₂₋₃₀-alkenyl and C₂₋₃₀-alkynyl can be substitutedby one or more —Si(R^(b))₃ or —OSi(R′)₃, or one or more CH₂ groups ofC₁₋₃₀-alkyl, C₂₋₃₀-alkenyl and C₂₋₃₀-alkynyl can be replaced by—Si(R^(b))₂— or —[Si(R^(b))₂—O]_(a)—Si(R^(b))₂—,

-   -   wherein R^(b) is at each occurrence C₁₋₁₀-alkyl, and a is an        integer from 1 to 20,

o and m are independently 0 or 1, and

Ar¹ and Ar² are independently arylene or heteroarylene, wherein aryleneand heteroarylene can be substituted with one or more C₁₋₃₀-alkyl,C₂₋₃₀-alkenyl, C₂₋₃₀-alkynyl, O—C₁₋₃₀ alkyl, aryl or heteroaryl, whichC₁₋₃₀-alkyl, C₂₋₃₀-alkenyl, C₂₋₃₀-alkynyl, O—C₁₋₃₀ alkyl, aryl andheteroaryl can be substituted with one or more C₁₋₂₀-alkyl,O—C₁₋₂₀-alkyl or phenyl,

L¹ and L² are independently selected from the group consisting of

wherein

Ar³ is at each occurrence arylene or heteroarylene, wherein arylene andheteroarylene can be substituted with one or more C₁₋₃₀-alkyl,C₂₋₃₀-alkenyl, C₂₋₃₀-alkynyl, O—C₁₋₃₀-alkyl, aryl or heteroaryl, whichC₁₋₃₀-alkyl, C₂₋₃₀-alkenyl, C₂₋₃₀-alkynyl, O—C₁₋₃₀-alkyl, aryl andheteroaryl can be substituted with one or more C₁₋₂₀-alkyl,O—C₁₋₂₀-alkyl or phenyl; and wherein adjacent Ar³ can be connected via aCR^(c)R^(c), SiR^(c)R^(c) or GeR^(c)R^(c) linker, wherein R^(c) is ateach occurrence H, C₁₋₃₀-alkyl or aryl, which C₁₋₃₀-alkyl and aryl canbe substituted with one or more C₁₋₂₀-alkyl, O—C₁₋₂₀-alkyl or phenyl,

p is at each occurrence an integer from 1 to 8, and

Ar⁴ is at each occurrence aryl or heteroaryl, wherein aryl andheteroaryl can be substituted with one or more C₁₋₃₀-alkyl, O—C₁₋₃₀alkyl or phenyl, which phenyl can be substituted with C₁₋₂₀-alkyl orO—C₁₋₂₀-alkyl,

or

-   -   ii) a diketopyrrolopyrrole-based small molecule of formulae (8)        or (9)

wherein

R³¹ is at each occurrence C₁₋₃₀-alkyl, C₂₋₃₀-alkenyl or C₂₋₃₀-alkynyl,wherein C₁₋₃₀-alkyl, C₂₋₃₀-alkenyl and C₂₋₃-alkynyl can be substitutedby —Si(R^(d))₃ or —OSi(R^(d))₃, or one or more CH₂ groups ofC₁₋₃₀-alkyl, C₂₋₃₀-alkenyl and C₂₋₃₀-alkynyl can be replaced by—Si(R^(d))₂— or —[Si(R^(d))₂—O]_(a)—Si(R^(d))₂—,

-   -   wherein R^(d) is at each occurrence C₁₋₁₀-alkyl, and a is an        integer from 1 to 20,

R³² is H, CN, C₁₋₂₀-alkyl, C₂₋₂₀-alkenyl, C₂₋₂₀-alkynyl, O—C₁₋₂₀ alkyl,aryl or heteroaryl, which C₁₋₂₀-alkyl, C₂₋₂₀-alkenyl, C₂₋₂₀-alkynyl,O—C₁₋₂₀ alkyl, aryl and heteroaryl can be substituted with one or moreC₁₋₆-alkyl, O—C₁₋₆-alkyl or phenyl,

x and y are independently 0 or 1, and

Ar⁵ and Ar⁶ are independently arylene or heteroarylene, wherein aryleneand heteroarylene can be substituted with one or more C₁₋₃₀-alkyl,C₂₋₃₀-alkenyl, C₂₋₃₀-alkynyl, O—C₁₋₃₀-alkyl, aryl or heteroaryl, whichC₁₋₃₀-alkyl, C₂₋₃₀-alkenyl, C₂₋₃₀-alkynyl, O—C₁₋₃₀-alkyl, aryl andheteroaryl can be substituted with one or more C₁₋₂₀-alkyl,O—C₁₋₂₀-alkyl or phenyl;

L³ and L⁴ are independently selected from the group consisting of

wherein

Ar⁷ is at each occurrence arylene or heteroarylene, wherein arylene andheteroarylene can be substituted with one or more C₁₋₃₀-alkyl,C₂₋₃₀-alkenyl, C₂₋₃₀-alkynyl, O—C₁₋₃₀-alkyl, aryl or heteroaryl, whichC₁₋₃₀-alkyl, C₂₋₃₀-alkenyl, C₂₋₃₀-alkynyl, O—C₁₋₃₀-alkyl, aryl andheteroaryl can be substituted with one or more C₁₋₂₀-alkyl,O—C₁₋₂₀-alkyl or phenyl; and wherein adjacent Ar⁷ can be connected viaan CR^(e)R^(e), SiR^(e)R^(e) or GeR^(e)R^(e) linker, wherein R^(e) is ateach occurrence H, C₁₋₃₀-alkyl or aryl, which C₁₋₃₀-alkyl and aryl canbe substituted with one or more C₁₋₂₀-alkyl, O—C₁₋₂₀-alkyl or phenyl,

q is at each occurrence an integer from 1 to 8, and

Ar⁸ is at each occurrence aryl or heteroaryl, wherein aryl andheteroaryl can be substituted with one or more C₁₋₃₀-alkyl,O—C₁₋₃₀-alkyl or phenyl, which phenyl can be substituted withC₁₋₂₀-alkyl or O—C₁₋₂₀-alkyl.

Examples of linear C₆₋₁₄-alkyl are n-hexyl, n-heptyl, n-octyl, n-nonyl,n-decyl, n-undecyl, n-dodecyl, n-undecyl, n-dodecyl, n-tridecyl andn-tetradecyl.

Examples of linear C₂₋₁₂-alkyl are ethyl, n-propyl, isopropyl, n-butyl,n-pentyl, n-hexyl. n-heptyl, n-octyl, n-nonyl, n-decyl, n-undecyl andn-dodecyl.

C₂₋₃₀-alkenyl can be branched or unbranched. Examples of C₂₋₃₀-alkenylare vinyl, propenyl, cis-2-butenyl, trans-2-butenyl, 3-butenyl,cis-2-pentenyl, trans-2-pentenyl, cis-3-pentenyl, trans-3-pentenyl,4-pentenyl, 2-methyl-3-butenyl, hexenyl, heptenyl, octenyl, nonenyl,docenyl, linoleyl (C₁₈), linolenyl (C₁₈), oleyl (C₁₈), and arachidonyl(C₂₀), and erucyl (C₂₂).

C₂₋₃₀-alkynyl can be branched or unbranched. Examples of C₂₋₃₀-alkynylare ethynyl, 2-propynyl, 2-butynyl, 3-butynyl, pentynyl, hexynyl,heptynyl, octynyl, nonynyl, decynyl, undecynyl, dodecynyl, undecynyl,dodecynyl, tridecynyl, tetradecynyl, pentadecynyl, hexadecynyl,heptadecynyl, octadecynyl, nonadecynyl and icosynyl (C₂₀).

Arylene is a bivalent aromatic ring system, consisting of one aromaticring or of two to eight condensed aromatic rings, wherein all rings areformed from carbon atoms. Preferably, arylene is a bivalent aromaticring system consisting of one aromatic ring or of two to four condensedaromatic rings, wherein all rings are formed from carbon atoms.

Heteroarylene is a bivalent aromatic ring system consisting of onearomatic ring or of two to eight condensed aromatic rings, wherein atleast one aromatic ring contains at least one heteroatom selected fromthe group consisting of S, O, N and Se. Preferably, heteroarylene is abivalent aromatic ring system consisting of one aromatic ring or of twoto four condensed aromatic rings, wherein at least one aromatic ringcontains at least one heteroatom selected from the group consisting ofS, O, N and Se.

Examples of heteroarylene are

wherein R^(k) is H, C₁₋₂₀-alkyl, aryl or heteroaryl, which C₁₋₂₀-alkyl,aryl and heteroaryl can be substituted with one or more C₁₋₆-alkyl,O—C₁₋₆-alkyl or phenyl.

Examples of adjacent Ar³, which are connected via a CR^(c)R^(c),SiR^(c)R^(c) or GeR^(c)R^(c) linker, wherein R^(c) is at each occurrenceH, C₁₋₃₀-alkyl or aryl, which C₁₋₃₀-alkyl and aryl can be substitutedwith one or more C₁₋₂₀-alkyl, O—C₁₋₂₀-alkyl or phenyl, and b is at eachoccurrence an integer from 1 to 8, are

Examples of adjacent Ar⁷, which are connected via an CR^(e)R^(e),SiR^(e)R^(e) or GeR^(e)R^(e) linker, wherein R^(e) is at each occurrenceH, C₁₋₃₀-alkyl or aryl, which C₁₋₃₀-alkyl and aryl can be substitutedwith one or more C₁₋₂₀-alkyl, O—C₁₋₂₀-alkyl or phenyl, and c is at eachoccurrence an integer from 1 to 8, are

Aryl is a monovalent aromatic ring system, consisting of one aromaticring or of two to eight condensed aromatic rings, wherein all rings areformed from carbon atoms. Preferably, aryl is a monovalent aromatic ringsystem consisting of one aromatic ring or of two to four condensedaromatic rings, wherein all rings are formed from carbon atoms.

Examples of aryl are

Heteroaryl is a monovalent aromatic ring system consisting of onearomatic ring or of two to eight condensed aromatic rings, wherein atleast one aromatic ring contains at least one heteroatom selected fromthe group consisting of S, O, N and Se. Preferably, heteroaryl is amonovalent aromatic ring system consisting of one aromatic ring or oftwo to four condensed aromatic rings, wherein at least one aromatic ringcontains at least one heteroatom selected from the group consisting ofS, O, N and Se.

Examples of heteroaryl are

wherein R^(m) is H, C₁₋₂₀-alkyl, aryl or heteroaryl, which C₁₋₂₀-alkyl,aryl and heteroaryl can be substituted with one or more C₁₋₆-alkyl,O—C₁₋₆-alkyl or phenyl.

Examples of L¹, L², L³ and L⁴ are

More preferably, the diketopyrrolopyrrole-based material is adiketopyrrolopyrrole-based polymer comprising units of formula (7) asdefined above.

The diketopyrrolopyrrole-based polymers comprising units of formula (7)can comprise other conjugated units. The diketopyrrolopyrrole-basedpolymers comprising units of formula (7) can be homopolymers orcopolymers. The copolymers can be random or block.

Preferably, the diketopyrrolopyrrole-based polymers comprise at least50% by weight of units of formula (7) based on the weight of thepolymer, more preferably at least 70%, even more preferably at least 90%by weight of units of formula (7) based on the weight of the polymer.Most preferably, diketopyrrolopyrrole-based polymers essentially consistof units of formula (7). The diketopyrrolopyrrole-based polymersessentially consisting of units of formula (7) can be homopolymers orcopolymers.

Even more preferably, the diketopyrrolopyrrole-based material is adiketopyrrolopyrrole-based polymer essentially consisting of units offormula

wherein

R³⁰ is C₆₋₃₀-alkyl,

o and m are independently 0 or 1, provided n and m are not both 0, and

Ar¹ and Ar² are independently

L¹ and L² are independently selected from the group consisting of

wherein

Ar³ is at each occurrence arylene or heteroarylene, wherein arylene andheteroarylene can be substituted with one or more C₁₋₃₀-alkyl,C₂₋₃₀-alkenyl, C₂₋₃₀-alkynyl, O—C₁₋₃₀-alkyl, aryl or heteroaryl, whichC₁₋₃₀-alkyl, C₂₋₃₀-alkenyl, C₂₋₃₀-alkynyl, O—C₁₋₃₀-alkyl, aryl andheteroaryl can be substituted with one or more C₁₋₂₀-alkyl,O—C₁₋₂₀-alkyl or phenyl; and wherein adjacent Ar³ can be connected via aCR^(c)R^(c), SiR^(c)R^(c) or GeR^(c)R^(c) linker, wherein R^(c) is ateach occurrence H, C₁₋₃₀-alkyl or aryl, which C₁₋₃₀-alkyl and aryl canbe substituted with one or more C₁₋₂₀-alkyl, O—C₁₋₂₀-alkyl or phenyl,

p is at each occurrence an integer from 1 to 8, and

Ar⁴ is at each occurrence aryl or heteroaryl, wherein aryl andheteroaryl can be substituted with one or more C₁₋₃₀-alkyl,O—C₁₋₃₀-alkyl or phenyl, which phenyl can be substituted withC₁₋₂₀-alkyl or O—C₁₋₂₀-alkyl.

Most preferably, the diketopyrrolopyrrole-based material is adiketopyrrolopyrrole-based polymer essentially consisting of units offormula

wherein

R³⁰ is

wherein

R^(f) is linear C₆₋₁₄-alkyl, and

R^(g) is linear C₂₋₁₂-alkyl,

o and m are independently 0 or 1, provided n and m are not both 0, and

Ar¹ and Ar² are

L¹ and L² are independently selected from the group consisting of

wherein

R^(h) and R^(i) are independently C₆₋₃₀-alkyl, and

r and s are independently 0 or 1.

In particular, the diketopyrrolopyrrole-based material is adiketopyrrolopyrrole-based copolymer essentially consisting of units offormulae

The composition comprising an organic semiconducting material can alsocomprise a solvent. The solvent can be any suitable solvent or solventmixture. Preferably, the solvent is a nonpolar aprotic solvent ormixture of nonpolar aprotic solvents. Examples of nonpolar aproticsolvents are toluene, xylene and mesitylene.

Preferably, the composition comprising an organic semiconductingmaterial also comprises a solvent and comprises from 0.01 to 10% byweight of the organic semiconducting material based on the weight of thecomposition. More preferably, the composition comprising an organicsemiconducting material is a solution and comprises from 0.1 to 5% byweight of the organic semiconducting material based on the composition.

The substrate for the top-gate, bottom-contact organic field effecttransistor can be any suitable substrate such as glass, or a plasticsubstrate such as silicon, polyethersulfone, polycarbonate, polysulfone,polyethylene terephthalate (PET) and polyethylene naphthalate (PEN).

The source and drain electrodes can be applied to the substrate by anysuitable technique such as sputtering, and patterned for example by alithography. The source and drain electrodes can be made from anysuitable material. Examples of suitable materials are gold (Au), silver(Ag), chromium (Cr) or copper (Cu), as well as alloys comprising atleast one of these metals. The source and drain electrodes can have athickness of 1 to 100 nm, preferably from 20 to 70 nm.

The channel length (L) of the organic field effect transistor, which isthe distance between source and drain electrode, is typically in therange of 5 to 100 μm.

The composition comprising the organic semiconducting material can beapplied on top of the source/drain electrodes by techniques known in theart. Preferably, the composition comprising the organic semiconductinglayer is applied by liquid processing techniques such as spin coating,blading, slot-die coating, drop-casting, spray-coating, ink-jetting orsoaking of the substrate of the electronic device in the composition.Preferably, the composition comprising the organic semiconducting layeris applied by spin-coating.

The semiconducting layer can be treated with heat at a temperature from40 to 120° C., preferably at a temperature from 70 to 100° C.

The semiconducting layer can have a thickness of 5 to 500 nm, preferablyof 10 to 100 nm.

The composition comprising the first dielectric material and acrosslinking agent carrying at least two azide groups can be applied ontop of semiconducting layer by techniques known in the art. Preferably,the composition comprising the first dielectric material and acrosslinking agent carrying at least two azide groups is applied byliquid processing techniques such as spin coating, blading, slot-diecoating, drop-casting, spray-coating, ink-jetting or soaking of thesubstrate of the electronic device in the composition. Preferably, thecomposition comprising the first dielectric material and a crosslinkingagent carrying at least two azide groups is applied by spin-coating.

The first dielectric layer can be treated with heat at a temperaturefrom 40 to 120° C., preferably at a temperature of from 70 to 100° C.

The first dielectric layer has a thickness of 10 to 2000 nm, preferablyof 50 to 1000 nm, more preferably of 100 to 500 nm.

Portions of the first dielectric layer can be cured by light treatmentusing a mask.

The light treatment is preferably performed at a low dosage such as at 5to 300 mJ/cm² more preferably at 20 to 150 mJ/cm², most preferably 50 to100 mJ/cm². Preferably, the light treatment is performed under ambientconditions. Ambient conditions refer to regular air, humidity andtemperature conditions. Preferably, the light treatment is UV lighttreatment and more preferably UV light treatment at a wavelength of 365nm.

The uncured portion of the first dielectric layer can be removed forexample by treatment with a suitable solvent such as propylene glycolmethyl ether acetate (PGMEA), which is also called wet-etching.

After the solvent treatment, the precursor of the top gate organic fieldeffect transistor can be dried by blowing with nitrogen and heating atelevated temperatures, for example at a temperature in the range of from70 to 100° C.

The portions of the semiconducting layer, that are not covered by thecured first dielectric layer, can be removed for example by etching outusing oxygen plasma treatment (100 sccm, 40 W, 2 minutes).

The channel length (L) of the organic field effect transistor istypically in the range of 3 to 2000 μm, preferably 3 to 20 μm.

The ration width (W)/length(L) of the organic field effect transistor isusually between 3/1 to 10/1.

Optionally a composition comprising a second dielectric material can beapplied on top of the first dielectric layer forming a second dielectriclayer. The composition comprising the second dielectric layer can beapplied by techniques known in the art. Preferably, the compositioncomprising the second dielectric material is applied by liquidprocessing techniques such as spin coating, blading, slot-die coating,drop-casting, spray-coating, ink-jetting or soaking of the substrate ofthe electronic device in the composition. Preferably, the compositioncomprising the second dielectric material is applied by spin-coating.

The second dielectric layer can be treated with heat at a temperaturefrom 40 to 120° C., preferably at a temperature of from 70 to 100° C.The second dielectric layer has a thickness of 10 to 2000 nm, preferablyof 50 to 1000 nm, more preferably of 100 to 500 nm.

The second dielectric material can be any dielectric material known inthe art or mixtures thereof. The dielectric material can be polystyrene(PS) and polystyrene derived polymers, poly(methylmethacrylate) (PMMA),poly(4-vinylphenol) (PVP), poly(vinyl alcohol) (PVA), benzocyclobutene(BCB) or polyimide (PI), or a star-shaped polymer as defined above.Preferably, the second dielectric material is polystyrene, apolystyrene-derived polymer or a star-shaped polymer as defined above.More preferably, the second dielectric material is a star-shaped polymeras defined above. If the second dielectric material is a star-shapedpolymer as defined above, it is preferred that the compositioncomprising a second dielectric material also comprises a secondcrosslinking agent carrying at least two azide groups and a solvent. Thedefinitions given for the crosslinking agent carrying at least two azidegroups and the solvent of the composition comprising the firstdielectric material also apply to the second crosslinking agent carryingat least two azide groups and the solvent of the composition comprisingthe second dielectric material.

If the second dielectric layer is formed from a composition comprising asecond dielectric material and a second crosslinking agent carrying atleast two azide groups, the second dielectric layer can also be cured bylight treatment.

The light treatment of the second dielectric layer is preferablyperformed at a low dosage such as at 5 to 300 mJ/cm², more preferably at20 to 150 mJ/cm², most preferably 50 to 100 mJ/cm². Preferably, thelight treatment is performed under ambient conditions. Ambientconditions refer to regular air, humidity and temperature conditions.Preferably, the light treatment is UV light treatment and morepreferably UV light treatment at a wavelength of 365 nm.

A gate electrode can be applied on top of the first dielectric layer or,if present, on top of the second dielectric layer, for example byevaporation using a mask. The gate electrode can be made from anysuitable gate material such as highly doped silicon, aluminium (Al),tungsten (W), indium tin oxide or gold (Au), or alloys comprising atleast one of these metals. The gate electrode can have a thickness of 1to 200 nm, preferably from 5 to 100 nm.

In the embodiment where a second dielectric layer is formed on top ofthe first dielectric layer, it is preferred that the step of curingportions of the first dielectric layer by light treatment is performedin a way that the cured first dielectric layer covers the path betweenthe source and drain electrodes and optionally also partially orcompletely covers the source and drain electrodes. It is more preferredthat the cured first dielectric layer covers the path between the sourceand drain electrodes and partially covers the source and drainelectrodes. As the cured first dielectric layer also functions as a“resist” to pattern the semiconducting layer, it is also preferred thatthe cured first dielectric layer and the semiconducting layer cover thepath between the source and drain electrodes, and optionally alsopartially or completely covers the source and drain electrodes. It ismore preferred that the cured first dielectric layer and thesemiconducting layer cover the path between the source and drainelectrodes and partially cover the source and drain electrodes. In thispreferred embodiment, the cured first dielectric layer and thesemiconducting layer do not extend beyond the source and drainelectrodes.

In the embodiment where a second dielectric layer is formed on top ofthe cured first dielectric layer, it is also preferred that thecomposition comprising a second dielectric material is applied on top ofthe cured first dielectric layer in a way that the cured firstdielectric layer and the semiconducting layer are embedded in the seconddielectric layer.

Also part of the present invention is a top-gate, bottom-contact organicfield effect transistor on a substrate, which organic field effecttransistor comprises source and drain electrodes, a semiconductinglayer, a cured first dielectric layer, a second dielectric layer and agate electrode, wherein

-   -   i) the cured first dielectric layer and the semiconducting layer        cover the path between the source and drain electrodes and        optionally also partially or completely cover the source and        drain electrodes, and    -   ii) the cured first dielectric layer and the semiconducting        layer are embedded in the second dielectric layer.

Preferred are top-gate, bottom-contact organic field effect transistoron a substrate, wherein the cured first dielectric layer is obtained by

-   -   i) applying a composition comprising a first dielectric material        and a crosslinking agent carrying a least two azide groups in        order to form a first dielectric layer, and    -   ii) by curing portions of the first dielectric layer by light        treatment in order to form a cured first dielectric layer,

wherein the first dielectric material comprises a star-shaped polymerconsisting of at least one polymer block A and at least two polymerblocks B, wherein each polymer block B is attached to the polymer blockA, and wherein at least 60 mol % of the repeat units of polymer block Bare selected from the group consisting of

wherein R¹, R², R³, R⁴, R⁵, R⁶, R⁷ and R⁸ are independently and at eachoccurrence H or C₁-C₁₀-alkyl.

More preferred are top-gate, bottom-contact organic field effecttransistors on a substrate, wherein the cured first dielectric layer andthe semiconducting layer cover the path between the source and drainelectrodes and partially cover the source and drain electrodes.

The process for the preparation of a top-gate, bottom-contact organicfield effect transistor on a substrate of the present invention isadvantageous as it allows the preparation of a cured first dielectriclayer of high film retention at low-dosage UV light treatment (5 to 300mJ/m²) under ambient conditions. Ambient conditions refer to ambientair, humidity and temperature conditions. Thus, the first dielectriclayer does not require inert gas atmosphere in order to be cured atlow-dosage UV radiation.

The film retention of the cured first dielectric layer refers to theratio d2/d1, wherein d1 is the thickness of the cured dielectric layerbefore washing (development) and d2 is the thickness of the cureddielectric layer after washing (development).

The cured first dielectric layer is highly stable towards solventdissolution. Thus, the next layer, for example an electrode materiallayer or another dielectric layer, can be applied without dissolving thecured first dielectric layer.

Depending on the crosslinking agent carrying at least two azide groupsused, UV light treatment of 365 nm can be used.

The process for the preparation of a top-gate, bottom-contact organicfield effect transistor on a substrate of the present invention isadvantageous as it yields transistors of improved performance, whereinthe semiconducting layer and the first dielectric layer are patternedtogether using low dosage UV light treatment under ambient conditions.The top gate organic field effect transistor shows improved performancesuch as high charge carrier mobility, low gate leakage current and/orhigh Ion/Ioff ratio.

The semiconducting layer can be formed from a composition comprising anorganic semiconducting material by solution processing techniques, andthe first dielectric layer can also be formed from a compositioncomprising a first dielectric layer and a crosslinking agent carrying atleast two azide groups by solution processing techniques. Thus, theprocess for preparation of top gate organic field effect transistor on asubstrate of the present invention is suitable for large-scaleproduction of transistors on flexible substrates.

The top-gate, bottom-contact organic field effect transistor of thepresent invention is advantageous as it shows a low gate leakagecurrent.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 shows an exemplary process for the preparation of a top gateorganic field effect transistor of the present invention. In step 1 thesource and drain electrodes are applied to the substrate. In step 2 thecomposition comprising an organic semiconducting material is applied inorder to form an organic semiconducting layer. In step 3 the compositioncomprising the first dielectric material and the crosslinking agentcarrying at least two azide groups is applied in order to form a firstdielectric layer. In Step 4, portions of the first dielectric layer(1^(st) GI) are treated with light in order to form a cured firstdielectric layer. In step 5 uncured portions of the first dielectriclayer are removed. In step 6, the portions of the organic semiconductinglayer not covered by the cured first dielectric layer are removed. Instep 7 a second dielectric layer (2^(nd) GI) is applied in a way thatthe first dielectric layer and the organic semiconducting layer areembedded in the second dielectric layer. In step 8, a gate electrode isapplied on top of the second dielectric layer.

FIG. 2 shows the cured first dielectric layer after development.

FIG. 3 shows the cured first dielectric layer as resist after theremoval of the portions of the semiconducting layer not covered by thecured first dielectric layer.

FIG. 4 shows the characteristics of the top gate organic field effecttransistor of example 3 measured with a Keithley 4200-SCS semiconductorcharacterization system. The drain current I_(ds) in relation to thegate voltage V_(gs) (transfer curve) for the organic field effecttransistor at a source voltage V_(ds) of −3 V respectively, −30 V isshown in FIG. 4 a . The drain current I_(ds) in relation to the drainvoltage V_(ds) (output curve) for the organic field effect transistor ata gate voltage V_(gs) of 0 V, −10 V, −20V and −30 V is shown in FIG. 4b.

EXAMPLES Example 1

Preparation of a star-shaped polymer, which is a triblock polymer havinga styrene-based inner block and two butadiene-based outer blocks with amass ratio styrene:butadiene of 90:10 and an amount of 1,2-addition ofbutadiene in the polybutadiene blocks of 73% based on the total amountof butadiene in the polybutadiene block

In a 10 L stainless steel reactor equipped with a cross-bar stirrer,4872 ml (3800 g) cyclohexane, 256 mL (200 g) THF and 1 g1,1-diphenylethylene (DPE) were heated to 30° C. and titrated withs-BuLi (1.4 M in cyclohexane) until a stable orange-red color remained(ca. 1.8 ml). Then, 7.14 mL s-BuLi (1.4 M in cyclohexane) was added tothe reaction mixture and immediately 76 mL (50 g) butadiene were addedunder stirring. The temperature was kept at 60° C. controlled by thereactor jacket temperature after 20 min 990 ml (900 g) styrene was addedslowly to keep the temperature at 50° C. by jacket counter-cooling.After 25 min another 76 mL (50 g) butadiene were added. After 20 min1.15 mL isopropanol was added and further stirred for 10 min. Thecolorless solution was transferred into two 5 Liter canisters and shakentogether with 25 mL water and 50 g dry ice each for purpose ofacidification.

Workup

The acidified mixture (solid content 20%) was precipitated into ethanol(10 fold volume containing 0.1% Kerobit TBK with respect to polymer),washed 3 times with 5 L ethanol and 3 times with 1 L distilled water ona Büchi funnel. Finally, the white powder was washed two times with 2.5L ethanol and four times with 250 mL ethanol and finally dried at 50° C.under vacuum for 24 h. The obtained white powder, triblock polymer P1,had the following characteristics: Mn=220000 g/mol. Mw=330000 g/mol (asdetermined by gel-permeation chromatography with polystyrene standards).PDI 1.5. Amount of 1,2-addition of butadiene in the polybutadieneblocks=73% (as determined by ¹H-NMR) based on the total amount ofbutadiene in the polybutadiene block.

Example 2

Preparation of Compositions A and B

Composition A is a solution of 8% by weight of P1 prepared as describedin example 1 as first dielectric material in a mixture of propyleneglycol monomethyl ether acetate (PGMEA) and cyclopentanone (CP) (70/30),and 4% by weight of2,7-bis[2-(4-azido-2,3,5,6-tetrafluorophenyl)ethynyl]-9-heptyl-9-hexyl-fluoreneas crosslinking agent carrying at least two azide groups based on theweight of P1. Composition A was prepared by mixing P1, the crosslinkingagent and the solvent.

Composition B is a solution of 0.75% by weight of thediketopyrrolopyrrole polymer of example 4 of WO2010/049321 as organicsemiconducting material in toluene. Formulation B was filtered through a0.45 micrometer polytetrafluoroethylene (PTFE).

Example 3

Preparation of a Top-Gate, Bottom-Contact Organic Field EffectTransistor Comprising Composition A and Composition B

Gold was sputtered on a polyethylene terephthalate substrate (PET) andpatterned using lithography. The obtained source and drain electrodeshad a thickness of approximately 50 nm. The channel length was 10 μm andthe channel width was 250 μm. Composition B prepared as described inexample 2 was applied on the source and drain electrodes by spin coating(1000 rpm, 30 seconds) and dried at 90° C. on a hot plate for 1 minuteto form a 50 nm thick semiconducting layer. Composition A prepared asdescribed in example 2 was applied on the semiconducting layer by spincoating (8000 rpm, 30 seconds), and dried at 80° C. on a hot plate for 2minutes to form a first dielectric layer having a thickness of 180 nm. Alithographic photomask was aligned on top of the first dielectric layer,and the exposed portions of the first dielectric layer were cured underambient conditions using light of 365 nm (radiation dosage 20 mJ/cm²,Suss Mask aligner MA6). The cured first dielectric layer was developedby immersing into propylene glycol methyl ether acetate (PGMEA) for 1minute followed by blowing with nitrogen and heating at 90° C. for 15minutes. The portions of the semiconducting layer, which were notcovered by the cured first dielectric layer, were etched out by oxygenplasma treatment (100 sccm, 40 W, 2 minutes). Composition A prepared asdescribed in example 2 was applied by spin coating (1500 rpm, 30seconds) to form a second dielectric film, which was dried at 80° C. ona hot plate for 2 minutes to obtain a 500 nm thick second dielectriclayer. The second dielectric layer was cured under ambient conditionsusing light of 365 nm (radiation dosage 20 mJ/cm², Suss Mask alignerMA6). Gate electrodes of gold having a thickness of approximately 50 nmwere evaporated through a shadow mask on top of the dielectric layer.

The characteristics of the top gate, bottom contact organic field effecttransistor were measured with a Keithley 4200-SCS semiconductorcharacterization system. The drain current I_(ds) in relation to thegate voltage V_(gs) (transfer curve) for the organic field effecttransistor at a source voltage V_(ds) of −3 V respectively, −30 V isshown in FIG. 4 a . The drain current I_(ds) in relation to the drainvoltage V_(ds) (output curve) for the organic field effect transistor ata gate voltage V_(gs) of 0 V, −10 V, −20V and −30 V is shown in FIG. 4b.

The average values of the charge carrier mobility μ, the I_(on)/I_(off)ratio (Vgs=−30 V), the onset voltage V_(on) and the gate leakage currentI_(g) [@ V_(gs)=−30V, V_(ds)=−30V] for the organic field effecttransistor (OFET) are given in table 1.

TABLE 1 Characterization of the OFET of example 3. I_(g) μI_(on)/I_(off) V_(on) (at V_(gs) = −30 V, [cm²/Vs] (V_(gs) = −30 V) [V]V_(ds) = −30 V) OFET example 3 0.48 8E+07 4 1.53E−13

The OFET of example 3 shows a very low gate leakage current I_(g).

Example 4

Evaluation of the Effect of the Radiation on the Retention of the CuredFirst Dielectric Layer Formed from Layers Formed from Composition A

Composition A prepared as described in example 2 was filtered through a1 micrometer filter and applied on a silicon dioxide substrate by spincoating (1800 rpm, 30 seconds). The wet dielectric layer was pre-bakedat 90° C. for 2 minutes on a hot plate to obtain a 400 nm thick layer.The dielectric layer was UV-cured using 365 nm (dose of 100 mJ/cm²)under ambient conditions.

Development of the dielectric layer was done by immersing the dielectriclayer into a mixture of propylene glycol monomethyl ether acetate(PGMEA) and cyclopentanone (CP) (70/30) for 1 minute followed by heatingat 90° C. for 5 minutes. The thickness of the dielectric layer wasmeasured after curing before development (d1) and after development (d2)using Veeco Dektak 150 to obtain the film retention ratio (d2/d1). Thefilm retention ratios (d2/d1) were determined.

The results are shown in table 2.

TABLE 2 styrene:butadiene cross-linker polymer Mn Mw 1,2-addition d2/d1Polymer [g:g] [%]^(a) type [g/mol] [g/mol] butadiene [%] [%] P1 90:10 3triblock 220000 330000 73 81

The cured dielectric layer formed from composition A shows a high filmretention.

The invention claimed is:
 1. A top-gate, bottom-contact organic fieldeffect transistor on a substrate, which top-gate, bottom-contact organicfield effect transistor comprises source and drain electrodes, asemiconducting layer, a cured first dielectric layer, a seconddielectric layer and a gate electrode, wherein i) the cured firstdielectric layer and the semiconducting layer cover the path between thesource and drain electrodes and optionally also partially or completelycover the source and drain electrodes, and ii) the cured firstdielectric layer and the semiconducting layer are embedded in the seconddielectric layer, wherein the cured first dielectric layer is thereaction product of a composition comprising a first dielectric materialand a crosslinking agent carrying a least two azide groups, wherein thefirst dielectric material comprises a star-shaped polymer consisting ofat least one polymer block A and at least two polymer blocks B, whereineach polymer block B is attached to the polymer block A, and wherein atleast 60 mol % of the repeat units of polymer block B are selected fromthe group consisting of

wherein R¹, R², R³, R⁴, R⁵, R⁶, R⁷ and R⁸ are independently and at eachoccurrence H or C₁₋₁₀-alkyl.
 2. The top-gate, bottom-contact organicfield effect transistor on a substrate of claim 1, wherein at least 80mol % of the monomer units of the polymer block B are selected from thegroup consisting of

wherein R¹, R², R³, R⁴, R⁵ and R⁶ are H.
 3. The top-gate, bottom-contactorganic field effect transistor on a substrate of claim 1, wherein atleast 80 mol % of the monomer units of polymer block A are selected fromthe group consisting of

wherein R²⁰, R²¹, R²², R²³, R²⁴, R²⁵ and R²⁶ are independently and ateach occurrence selected from the group consisting of H, C₆₋₁₄-aryl, 5to 14 membered heteroaryl and C₁₋₃₀-alkyl, and R^(a) is C(O)OH,C(O)OC₁₋₃₀-alkyl, C(O)—H, C(O)C₆₋₁₄-aryl, C(O)N(C₁₋₃₀-alkyl)₂,C(O)N(C₆₋₁₄-aryl)₂, C(O)N(C₁₋₃₀-alkyl)(C₆₋₁₄-aryl), C(O)—C₆₋₁₄-aryl,C(O)—C₁₋₃₀-alkyl, O—C₆₋₁₄-aryl, O—C₁₋₃₀-alkyl, OC(O)C₁₋₃₀-alkyl,OC(O)C₆₋₁₄-aryl or CN, wherein C₆₋₁₄-aryl and 5-14 membered heteroarylcan be substituted with one or more substituents selected from the groupconsisting of C₁₋₁₀-alkyl, C(O)OH, C(O)OC₁₋₁₀-alkyl, C(O)phenyl,C(O)N(C₁₋₁₀-alkyl)₂, C(O)N(phenyl)₂, C(O)N(C₁₋₁₀-alkyl)(phenyl),C(O)-phenyl, C(O)—C₁₋₁₀-alkyl, OH, O-phenyl, O—C₁₋₁₀-alkyl,OC(O)-phenyl, CN and NO₂, and C₁₋₃₀-alkyl can be substituted with one ormore substituents selected from the group consisting of phenyl, C(O)OH,C(O)OC₁₋₁₀-alkyl, C(O)phenyl, C(O)N(C₁₋₁₀-alkyl)₂, C(O)N(phenyl)₂,C(O)N(C₁₋₁₀-alkyl)(phenyl), C(O)-phenyl, C(O)—C₁₋₁₀-alkyl, O-phenyl,O—C₁₋₁₀-alkyl, OC(O)C₁₋₁₀-alkyl, OC(O)-phenyl, Si(C₁₋₁₀-alkyl)₃,Si(phenyl)₃, CN and NO₂, n is an integer from 1 to 3, and L²⁰ isC₁₋₁₀-alkylene, C₂₋₁₀-alkenylene, C₂₋₁₀-alkynylene, C₆₋₁₄-arylene orS(O).
 4. The top-gate, bottom-contact organic field effect transistor ona substrate of claim 3, wherein at least 90 mol % of the monomer unitsof polymer block A is a monomer unit selected from the group consistingof

wherein R²⁰ and R²¹ are independently selected from the group consistingof H and C₆₋₁₄-aryl, wherein C₆₋₁₄-aryl can be substituted with one ormore C₁₋₁₀-alkyl, and L²⁰ is C₆₋₁₄-arylene.
 5. The top-gate,bottom-contact organic field effect transistor on a substrate of claim1, wherein the star-shaped polymer is a triblock polymer consisting ofone polymer block A and two polymer blocks B, wherein each polymer blockB is attached to the polymer block A, and wherein at least 60 mol % ofthe monomer units of polymer block B are selected from the groupconsisting of

wherein R¹, R², R³, R⁴, R⁵, R⁶, R⁷ and R⁸ are independently and at eachoccurrence H or C₁₋₄-alkyl, with the proviso that at least one of themonomer units (1A) and (1B) is present, and that the ratio of [mols ofmonomer units (1A) and (1B)]/[mols of monomer units (1A), (1B), (1C) and(1D)] is at least 30%.
 6. The top-gate, bottom-contact organic fieldeffect transistor on a substrate of claim 5, wherein at least 80 mol %of the monomer units of the polymer block B of the triblock polymer areselected from the group consisting of

wherein R¹, R², R³, R⁴, R⁵ and R⁶ are H, with the proviso that at leastone of the monomer units (1A) and (1B) is present, and that the ratio of[mols of monomer units (1A) and (1B)]/[mols of monomer units (1A), (1B),(1C) and (1D)] is at least 70%.
 7. The top-gate, bottom-contact organicfield effect transistor on a substrate of claim 5, wherein at least 80mol % of the monomer units of polymer block A of the triblock polymerare selected from the group consisting of

wherein R²⁰, R²¹, R²², R²³, R²⁴, R²⁵ and R²⁶ are independently and ateach occurrence selected from the group consisting of H, C₆₋₁₄-aryl, 5to 14 membered heteroaryl and C₁₋₃₀-alkyl, and R^(a) is C(O)OH,C(O)OC₁₋₃₀-alkyl, C(O)—H, C(O)C₆₋₁₄-aryl, C(O)N(C₁₋₃₀-alkyl)₂,C(O)N(C₆₋₁₄-aryl)₂, C(O)N(C₁₋₃₀-alkyl)(C₆₋₁₄-aryl), C(O)—C₆₋₁₄-aryl,C(O)—C₁₋₃₀-alkyl, O—C₆₋₁₄-aryl, O—C₁₋₃₀-alkyl, OC(O)C₁₋₃₀-alkyl,OC(O)C₆₋₁₄-aryl or CN, wherein C₆₋₁₄-aryl and 5 to 14 memberedheteroaryl can be substituted with one or more substituents selectedfrom the group consisting of C₁₋₁₀-alkyl, C(O)OH, C(O)OC₁₋₁₀-alkyl,C(O)phenyl, C(O)N(C₁₋₁₀-alkyl)₂, C(O)N(phenyl)₂,C(O)N(C₁₋₁₀-alkyl)(phenyl), C(O)-phenyl, C(O)—C₁₋₁₀-alkyl, OH, O-phenyl,O—C₁₋₁₀-alkyl, OC(O)C₁₋₁₀-alkyl, OC(O)-phenyl, CN and NO₂, andC₁₋₃₀-alkyl can be substituted with one or more substituents selectedfrom the group consisting of with phenyl, C(O)OH, C(O)OC₁₋₁₀-alkyl,C(O)phenyl, C(O)N(C₁₋₁₀-alkyl)₂, C(O)N(phenyl)₂,C(O)N(C₁₋₁₀-alkyl)(phenyl), C(O)-phenyl, C(O)—C₁₋₁₀-alkyl, O-phenyl,O—C₁₋₁₀-alkyl, OC(O)C₁₋₁₀-alkyl, OC(O)-phenyl, Si(C₁₋₁₀-alkyl)₃,Si(phenyl)₃, CN and NO₂, n is an integer from 1 to
 3. 8. The top-gate,bottom-contact organic field effect transistor on a substrate of claim7, wherein at least 80 mol % of the monomer units of polymer block A ofthe triblock polymer are monomer units selected from the groupconsisting of

wherein R²⁰ and R²¹ are independently selected from the group consistingof H and C₆₋₁₄-aryl, wherein C₆₋₁₄-aryl can be substituted with one ormore C₁₋₁₀-alkyl.
 9. The top-gate, bottom-contact organic field effecttransistor on a substrate of claim 1, wherein the weight ratio ofpolymer block A/total polymer blocks B is from 60/40 to 96/4.
 10. Thetop-gate, bottom-contact organic field effect transistor on a substrateof claim 1, wherein the star-shaped polymers have a number averagemolecular weight Mn of at least 60000 g/mol and a weight averagemolecular weight Mw of at least 70000 g/mol, both as determined by gelpermeation chromatography.
 11. The top-gate, bottom-contact organicfield effect transistor on a substrate of claim 1, wherein thecrosslinking agent carrying at least two azide groups is a crosslinkingagent carrying two azide groups and is of formula

wherein a is 0 or 1, R⁵⁰ is at each occurrence selected from the groupconsisting of H, halogen, SO₃M and C₁₋₂₀-alkyl, which C₁₋₂₀-alkyl can besubstituted with one or more halogen, wherein M is H, Na, K or Li, andL⁵⁰ is a linking group.
 12. The top-gate, bottom-contact organic fieldeffect transistor on a substrate of claim 1, wherein the seconddielectric layer comprises a composition comprising a second dielectricmaterial.
 13. The top-gate, bottom-contact organic field effecttransistor on a substrate of claim 12, wherein the cured firstdielectric layer and the semiconducting layer partially or completelycover the source and drain electrodes.
 14. A top-gate, bottom-contactorganic field effect transistor on a substrate, which top-gate,bottom-contact organic field effect transistor comprises source anddrain electrodes, a semiconducting layer, a cured first dielectriclayer, a second dielectric layer and a gate electrode, wherein i) thecured first dielectric layer and the semiconducting layer cover the pathbetween the source and drain electrodes and optionally also partially orcompletely cover the source and drain electrodes, and ii) the curedfirst dielectric layer and the semiconducting layer are embedded in thesecond dielectric layer, wherein the semiconducting layer comprises anorganic semiconducting material comprising at least onediketopyrrolopyrrole-based material, wherein thediketopyrrolopyrrole-based material is either i) adiketopyrrolopyrrole-based polymer comprising units of formula

wherein R³⁰ is at each occurrence C₁₋₃₀-alkyl, C₂₋₃₀-alkenyl orC₂₋₃₀-alkynyl, wherein C₁₋₃₀-alkyl, C₂₋₃₀-alkenyl and C₂₋₃₀-alkynyl canbe substituted by one or more —Si(R^(b))₃ or —Oi(R^(b))₃, or one or moreCH₂ groups of C₁₋₃₀-alkyl, C₂₋₃₀-alkenyl and C₂₋₃₀-alkynyl can bereplaced by —Si(R^(b))₂- or -[Si(R^(b))₂—O]_(a)—Si(R^(b))₂-, whereinR^(b) is at each occurrence C₁₋₁₀-alkyl, and a is an integer from 1 to20, o and m are independently 0 or 1, and Ar¹ and Ar² are independentlyarylene or heteroarylene, wherein arylene and heteroarylene can besubstituted with one or more C₁₋₃₀-alkyl, C₂₋₃₀-alkenyl, C₂₋₃₀-alkynyl,O—C₁₋₃₀-alkyl, aryl or heteroaryl, which C₁₋₃₀-alkyl, C₂₋₃₀-alkenyl,C₂₋₃₀-alkynyl, O—C₁₋₃₀-alkyl, aryl and heteroaryl can be substitutedwith one or more C₁₋₂₀-alkyl, O—C₁₋₂₀-alkyl or phenyl, L¹ and L² areindependently selected from the group consisting of

wherein Ar³ is at each occurrence arylene or heteroarylene, whereinarylene and heteroarylene can be substituted with one or moreC₁₋₃₀-alkyl, C₂₋₃₀-alkenyl, C₂₋₃₀-alkynyl, O—C₁₋₃₀-alkyl, aryl orheteroaryl, which C₁₋₃₀-alkyl, C₂₋₃₀-alkenyl, C₂₋₃₀-alkynyl,O—C₁₋₃₀-alkyl, aryl and heteroaryl can be substituted with one or moreC₁₋₂₀-alkyl, O—C₁₋₂₀-alkyl or phenyl; and wherein adjacent Ar³ can beconnected via a CR^(c)R^(c), SiR^(c)R^(c) or GeR^(c)R^(c) linker,wherein R^(c) is at each occurrence H, C₁₋₃₀-alkyl or aryl, whichC₁₋₃₀-alkyl and aryl can be substituted with one or more C₁₋₂₀-alkyl,O—C₁₋₂₀-alkyl or phenyl, p is at each occurrence an integer from 1 to 8,and Ar⁴ is at each occurrence aryl or heteroaryl, wherein aryl andheteroaryl can be substituted with one or more C₁₋₃₀-alkyl,O—C₁₋₃₀-alkyl or phenyl, which phenyl can be substituted withC₁₋₂₀-alkyl or O—C₁₋₂₀-alkyl, or ii) a diketopyrrolopyrrole-based smallmolecule of formulae (8) or (9)

wherein R³¹ is at each occurrence C₁₋₃₀-alkyl, C₂₋₃₀-alkenyl orC₂₋₃₀-alkynyl, wherein C₁₋₃₀-alkyl, C₂₋₃₀-alkenyl and C₂₋₃₀-alkynyl canbe substituted by —Si(R^(d))₃ or —OSi(R^(d))₃, or one or more CH₂ groupsof C₁₋₃₀-alkyl, C₂₋₃₀-alkenyl and C₂₋₃₀-alkynyl can be replaced by—Si(R^(d))₂- or -[Si(R^(d))₂—O]_(a)—Si(R^(d))₂-, wherein R^(d) is ateach occurrence C₁₋₁₀-alkyl, and a is an integer from 1 to 20, R³² is H,CN, C₁₋₂₀-alkyl, C₂₋₂₀-alkenyl, C₂₋₂₀-alkynyl, O—C₁₋₂₀-alkyl, aryl orheteroaryl, which C₁₋₂₀-alkyl, C₂₋₂₀-alkenyl, C₂₋₂₀-alkynyl,O—C₁₋₂₀-alkyl, aryl and heteroaryl can be substituted with one or moreC₁₋₆-alkyl, O—C₁₋₆-alkyl or phenyl, x and y are independently 0 or 1,and Ar⁵ and Ar⁶ are independently arylene or heteroarylene, whereinarylene and heteroarylene can be substituted with one or moreC₁₋₃₀-alkyl, C₂₋₃₀-alkenyl, C₂₋₃₀-alkynyl, O—C₁₋₃₀-alkyl, aryl orheteroaryl, which C₁₋₃₀-alkyl, C₂₋₃₀-alkenyl, C₂₋₃₀-alkynyl,O—C₁₋₃₀-alkyl, aryl and heteroaryl can be substituted with one or moreC₁₋₂₀-alkyl, O—C₁₋₂₀-alkyl or phenyl; L³ and L⁴ are independentlyselected from the group consisting of

wherein Ar⁷ is at each occurrence arylene or heteroarylene, whereinarylene and heteroarylene can be substituted with one or moreC₁₋₃₀-alkyl, C₂₋₃₀-alkenyl, C₂₋₃₀-alkynyl, O—C₁₋₃₀-alkyl, aryl orheteroaryl, which C₁₋₃₀-alkyl, C₂₋₃₀-alkenyl, C₂₋₃₀-alkynyl,O—C₁₋₃₀-alkyl, aryl and heteroaryl can be substituted with one or moreC₁₋₂₀-alkyl, O—C₁₋₂₀-alkyl or phenyl; and wherein adjacent Ar⁷ can beconnected via an CR^(e)R^(e), SiR^(e)R^(e) or GeR^(e)R^(e) linker,wherein R^(e) is at each occurrence H, C₁₋₃₀-alkyl or aryl, whichC₁₋₃₀-alkyl and aryl can be substituted with one or more C₁₋₂₀-alkyl,O—C₁₋₂₀-alkyl or phenyl, q is at each occurrence an integer from 1 to 8,and Ar⁸ is at each occurrence aryl or heteroaryl, wherein aryl andheteroaryl can be substituted with one or more C₁₋₃₀-alkyl,O—C₁₋₃₀-alkyl or phenyl, which phenyl can be substituted withC₁₋₂₀-alkyl or O—C₁₋₂₀-alkyl.